Tracheotomy is a surgical procedure frequently performed to relieve obstruction of airflow through the larynx and upper trachea. One of its main side effects is loss of essential breathing functions including warming and filtering of air, coughing, smelling, tasting, swallowing, and, more devastatingly, speaking. Voice production requires vibration of the vocal cords from a stream of air passing through the larynx. When a tracheotomy tube is present, exhaled air follows the path of least resistance, and exits through the tracheotomy tube rather than up towards the larynx, limiting vibratory movement of the vocal cords, and hence limiting perceptual speech. This creates a psychological hardship, as communication is critical to patients' overall medical care and social interactions This problem can be particularly disruptive in children, where a tracheotomy can actually impact the development of normal language skills
In order to redirect the air toward the vocal cords, the patient may use a finger to occlude the tracheotomy tube. Finger occlusion however has several limitations: it requires manual dexterity (which some patients may lack); it also requires coordination of phonation with breathing (which some patients may be unable to perform); and it is unsanitary. The use of a tracheotomy speaking valve enables tracheotomy patients to speak without having to occlude the tracheotomy tube with their finger. Unidirectional speaking valves have a displaceable element that allows air to flow through the cannula and into the lungs during inspiration and prevent air from flowing through the cannula during expiration. Thus, during expiration, air flows through the patient's upper airways, such as the subglottic trachea, larynx, pharynx, mouth, and nasal passages. As a result, tracheotomized individuals using a unidirectional tracheotomy valve are able to communicate orally and maintain clear upper airway passages by coughing or expelling air through the upper airway passages.
There are a number of unidirectional (one-way) speaking valves that close 100% upon exhalation (also referred to as “no leak” design valves), redirecting air from the tracheostomy tube upward through the larynx, permitting phonation and improvement of swallowing and of secretions management. These are flapper-type speaking valves, whereby a diaphragm abuts the frontal opening of the valve. The valve opens upon inhalation and forms an uninterrupted a tight closed no-leak seal upon exhalation, hence completely stopping the air from exiting through the tracheostomy valve upon exhalation. Such one-way flapper valves include for example: the Passy-Muir tracheostomy & ventilator swallowing and speaking valve (PMV 005) available from Passy-Muir Inc, the Montgomery tracheostomy speaking valve (product code 221201) and TRACOE® PhonAssist speaking valve (product code 650-T), both available from Boston Medical Products; the Hood speaking valve (product code SPV-3015); and the Shiley Phonate® speaking valve (product designation SSVO) available from Nellcor Puritan-Bennett LLC. These valves are generally of a similar size and configuration and are designed to slide onto a standard 15 millimeter (mm) external (ventilator) end of a tracheostoma tube or cannula. Also, prior U.S. Pat. No. 8,051,856 Bare & Scherer, assigned to Passy-Muir, Inc U.S. Pat. No. 802,316 by Fulgham describe similar types of flapper unidirectional speaking valves having a “no leak” design. This listing is not intended to be a representation that a complete search of all relevant art has been made, or that no more pertinent art than that listed exists, or that the listed art is material to patentability. Nor should any such representation be inferred.
Another type of valve, which is different from flapper type valves, is a unidirectional tracheotomy speaking valve with an external cylindrical housing chamber, that contains a ball acting as the displaceable element. The ball moves back and forth during inspiration and expiration, and is limited from going beyond the housing chamber during inspiration by a pin or a wire that extends into the posterior opening of the chamber and intersects a path of travel of the ball, preventing it from entering the patient's airway. In this design, the housing chamber is external to the tracheotomy tube and coupled to the cannula of a tracheotomy tube. U.S. Pat. No. 6,588,428 by Shikani et al describes a similar design unidirectional speaking valve except the housing chamber is internal and an integral part of the inner cannula of the tracheotomy tube.
One common clinical observation to the above unidirectional speaking valves is that, because all the valves close 100% and allow no air leak upon exhalation, airflow is always redirected to the vocal cords at exhalation. Hence, while the tracheotomized patient can breathe in through the speaking valve, he/she never has the possibility to breath out through the valve if he/she wishes (for example, while the patient is at rest and does not wish or need to redirect the air upward through the vocal cords in order to speak). Consequently the patient is not able to use any of these speaking valves concurrently with a Humidity Moisture Exchanger (HME) to benefit from humidification and filtration. Another concern is that, in order for the tracheotomized patient who is on the ventilator and who wishes to use a unidirectional speaking valve, the tracheotomy tube cuff must be deflated in order for the air to go around the tube and up towards the vocal cords, otherwise not only will voicing be impossible, but there is also a risk of complete closure of the airway circuit, a potentially life-threatening situation. In order to address these concerns, a different type of valve is required to allow at least some degree (even if slight) of air leak upon exhalation.
One of the purposes of the present disclosure is to describe a novel unidirectional speaking valve and a method to allow redirecting air from the tracheostomy tube upward through the larynx, permitting phonation and improvement of swallowing and of secretions management, with some degree (even if slight) of air leak without 100% closure of the airway circuit.
For a variety of reasons, patients may find themselves in respiratory failure that necessitates a tracheotomy and ventilator support. These conditions may include progressive respiratory insufficiency due for example to muscular dystrophies, post-polio syndrome, amyotrophic lateral sclerosis (ALS or Lou Gehrig's disease), severe deformities of the chest wall or spine, such as kyphoscoliosis or thoracoplasty. Acute respiratory failure may also require tracheotomy and mechanical support, due for example to acute neurologic events, strokes, high spinal cord injury acute pulmonary infections, upper airway obstructive lesions, etc.
Communication for handicapped ventilator-dependent patients is a difficult problem both for the patient and the healthcare personnel. Tracheotomy diverts air away from the vocal cords and interferes with the production of normal speech. This may be addressed by using a one-way speaking valve, which redirects the air flow toward the larynx.
Currently, there are only two single unidirectional valves that are available for use with the ventilator: the Passy-Muir tracheostomy speaking valve and the Montgomery® Ventrach™ Speaking Valve. These two devices are flapper type valves, hence allow air to enter the lungs through the tracheostomy tube but close 100% upon exhalation.
As previously mentioned, a critically important point for using the Passy-Muir or the Montgomery® Ventrach™ tracheostomy speaking valve concurrently with a ventilator is that the tracheotomy cuff must be deflated (to redirect airflow upward toward the vocal cords), otherwise there is risk of a dangerous closed airway circuit.
While cuff deflation is a must, it does create conditions which make it fairly difficult to introduce the ventilator patient to a speaking valve for the first time. Even though tracheotomized patients are eager to speak, there is significant patient reluctance toward cuff deflation, and it hence requires quite a bit of preparation and counseling on behalf of the speech-language pathologist to ensure that both the patient and family feel comfortable with speaking valve use while on a ventilator. Introducing the valve begins with an initial goal of restoring airflow through cuff deflation trials. The duration of the trials depends on the patient's medical status as well as ventilator settings and tracheotomy size. One particular patient may tolerate full cuff deflation within a couple of sessions, and another patient may only tolerate partial deflation trials over a period of weeks. The patient's tolerance to cuff deflation is determined by any changes in heart rate, desaturation, CO2 levels and voicing. If there are no adverse changes with full cuff deflation, the speech-language pathologist generally can then move forward with a speaking valve trial. However, some patients, such as those who have significantly compromised pulmonary status, such as an upper-airway obstruction or a particularly large or specialized tracheostomy tube, may not tolerate cuff deflation and may not even be candidates for speaking valves.
If, by mistake, the nurse or the medical staff introduce the speaking valve in the circuit and forget to deflate the cuff while the patient is hooked to the ventilator, this will result in a closed airway circuit, whereby air is blown by the ventilator into the trachea but the patient is not be able to exhale, since the valve is sealed and there is also an airtight seal around the tracheostomy tube. This will cause a hazardous increase in trans-tracheal pressure, subsequent hypo-oxygenation, hypercapnea and potentially even cause death of the patient. As a matter of fact, several such close call situations have been observed over the last few years due to this particular error by nurses and medical staff, and even worse, an accidental death of a paraplegic tracheotomized patient on the ventilator was recently documented.
Other than deflating a cuffed tracheotomy tube, the treating physician may opt to use a cuffless tracheostomy tube, or even a fenestrated tracheotomy tube. The problem is that, because of their lung physiology, many ventilator dependent patients are unable to tolerate the significant air leak observed with fenestrated tracheotomy tubes, cuffless and/or uncuffed tracheostomy tubes. These patients will then miss out on the advantages of a speaking valve, and end up forgoing the option of speech. They will also miss out on other benefits of speaking valves, including reduced secretions, increased sense of smell, reduced aspiration, and increased amount of oxygen in the blood. The treating physician may opt to manipulate the ventilator settings in order to help overcome some of the air leak in uncuffed ventilated patients with a tracheostomy; for example, they can try prolonging the inspiratory time using PEEP (positive end-expiratory pressure). The use of a longer inspiratory time and higher PEEP are additive in their ability to improve speaking rate; however, there are many patients who are unable to tolerate ventilator setting manipulations due to their physiology.
The above clinical observations of problems encountered by tracheotomy patients on ventilators (including the necessity to deflate the cuff in order to introduce the ventilator patient to a speaking valve, difficulty tolerating cuff deflation, risk of human error of erroneously inflating the cuff and causing hazardous increase in trans-tracheal pressure and hypercapnea) prompted the present inventors to invent a new type of valve designed to solve, in at least some embodiments, the problem of “no leak” valves. This, a new type of valve, is unique in a sense that it does not close 100% upon exhalation.